Fig. 1.

Non–Ca²⁺-conducting Ca²⁺ channels in larval zebrafish skeletal myotubes. (A) Depolarizing test pulses to potentials unto +70 mV were unable to elicit Ca²⁺ currents at any potential (n = 14). (B) Robust voltage-dependent α_1S gating is indicated by charge movements with a Q_max value of 10.45 ± 0.58 nC/μF and a half-maximal activation of −4.21 ± 1.36 mV (n = 20), assessed by integrating the “ON” component of α_1S gating currents (Q_on). (C) Depolarization-induced intracellular Ca²⁺ transients had a (ΔF/F₀) _max value of 4.44 ± 0.42 with half-maximal activation at −10.39 ± 0.75 mV (n = 17). (D) Also, 10 mM Ba²⁺ instead of 10 mM Ca²⁺ as a charge carrier did not awake any current at any potential (n = 6).